Rapid and highly selective dipchecking for cyanide ions in aqueous media.

This article reports a simple dipping method for the detection of cyanide ions in water and biological samples, such as blood, using chitosan-gold nanoparticle (CH-Au NP) composite films prepared using CH-Au NP colloids. Here, gold nanoparticles were generated by heating (to ~80 °C) a solution of chitosan and gold chloride, where chitosan plays the dual role of reducing and stabilizing agent. The well-known chemistry of leaching of gold by cyanide is exploited here to detect cyanide ions.

Naked eye detection of glucose in urine using glucose oxidase immobilized gold nanoparticles.

Colloidal gold is extensively used for molecular sensing because of the flexibilities it offers in terms of modification of the gold nanoparticle surface with a variety of functional groups using thiol chemistry. We describe a simple assay that allows the visual detection of glucose in aqueous samples and demonstrates its applicability by estimating glucose in urine. To enable the glucose detection, we functionalized the thiol capped gold nanoparticles with glucose oxidase, the enzyme specific to β-D glucose, using carbodiimide chemistry.

Poly(methyl methacrylate)-grafted chitosan microspheres for controlled release of ampicillin.

Microspheres of 50-500 microm diameter were prepared from a blend of chitosan and chitosan-g-PMMA. Environmental scanning electron microscopic and SEM studies revealed that the microspheres are porous and the pores extend toward the inner core of the microspheres. The microspheres were also found to be hemocompatible and cytocompatible.